> I'm not sure why anybody would generate UUIDs in browsers though, it seems to defeat the purpose.

How about for offline-first apps?

Tell that to Segment. Hopefully they've fixed that, but they didn't seem to think it was a problem years ago (spoiler: it was a big problem).

When you do CQRS, you basically have to generate some form of unique identifier in the client. Why not a UUID in the browser?